Ian Fleming

• PhD
• Professor (Full) at Memorial University of Newfoundland

Substantial domestication associated divergence of farmed from wild Atlantic salmon has raised concerns regarding the negative impacts of farm escapees on the genetic integrity and adaptability of wild salmon populations. Studies from across the North Atlantic have repeatedly demonstrated the presence of hybridization and introgression from escapee...

Escape of genetically distinct farmed Atlantic salmon (Salmo salar) raises concerns about their potential interactions with wild populations and the disruption of local adaptation through genetic admixture. It is often unknown whether genetic origin or common domestication effects will have a greater influence on consequences posed by escaped farme...

Mass mortality events (MMEs) are defined as the death of large numbers of fish over a short period of time. These events can result in catastrophic losses to the Atlantic salmon aquaculture industry and the local economy. However, they are challenging to understand because of their relative infrequency and the high number of potential factors invol...

Farming of Atlantic salmon Salmo salar has resulted in highly domesticated individuals, with notable genetic and phenotypic differences from their wild counterparts. Understanding how interbreeding with aquaculture escapees affects wild, often at-risk populations is increasingly essential to conservation efforts. Here, we used an experimental relea...

An understanding of genetic differences in fitness-related traits for farm, wild, and hybrid Atlantic salmon (Salmo salar) is key for predicting impacts of aquaculture escapes on wild populations. Here we used lipid and fatty acid (FA) analyses to investigate differences in storage and foraging ability among Atlantic salmon juveniles of three cross...

Selection due to multi-generational domestication and genetically distinct origins raise concerns about potential fitness consequences of hybridization between farmed and wild Atlantic salmon. In Newfoundland (NF), Canada, the aquaculture industry uses the North American (NA) Saint John River strain, though site-specific permission has been granted...

Gene flow between wild and domestic populations has been repeatedly demonstrated across a diverse range of taxa. Ultimately, the genetic impacts of gene flow from domestic into wild populations depends both on the degree of domestication and the original source of the domesticated population. Atlantic Salmon, Salmo salar, used in North American aqu...

The escape of domesticated Atlantic salmon Salmo salar from aquaculture facilities represents a continued threat to the genetic and demographic stability of wild salmon stocks. Escaped farm-origin salmon have been shown to hybridize with wild conspecifics, yet the long-term genetic impacts are generally unknown. Theoretically, life history variatio...

The escape of Atlantic salmon Salmo salar from aquaculture has been identified as a significant threat to the persistence and stability of wild salmon populations. Yet the magnitude of phenotypic impacts due to hybridization remains largely unresolved. We evaluated the phenotypic consequences of hybridization using geometric morphometrics both unde...

Due to multi‐generation domestication selection, farmed and wild Atlantic salmon diverge genetically, which raises concerns about potential genetic interactions among escaped farmed and wild populations and disruption of local adaptation through introgression. When farmed strains of distant geographic origin are used, it is unknown whether the gene...

Use of fast‐growing domesticated and/or genetically modified strains of fish is becoming increasingly common in aquaculture, increasing the likelihood of deliberate or accidental introductions into the wild. To date, their ecological impacts on ecosystems remain to be quantified. Here, using a controlled phenotype manipulation by implanting growth...

Although historical records of introductions that trigger successful biological invasions are common, subsequent patterns of dispersal and colonisation routes are unclear. We use microsatellites to examine genetic population structuring of established invasive brown trout (Salmo trutta) populations in Newfoundland, Canada, for evidence of “natural”...

Using nonlethal tissue biopsies, we investigated somatic energy, lipid composition, and condition in post-spawned Atlantic salmon (Salmo salar) (kelts, n = 69) returning to sea in the spring and explored contrasts as a function of previous migration and spawning history, length and sex. Using mark–recapture analysis, we also explored linkages betwe...

It has long been clear that interbreeding between domesticated and wild Atlantic salmon can lead to negative fitness consequences for native populations. Few studies, however, have examined these consequences at critical early life stages, particularly in the context of distinct geographical and ancestral relationships among populations as well dom...

When escapee farmed Atlantic salmon Salmo salar interbreed with wild fish, the introgression of maladaptive genes can lower wild population productivity and alter key life history traits. To date, only a few European studies have compared wild, farm, and hybrid salmon under common conditions in the wild, isolating the influence of genetics on survi...

Cultured Atlantic salmon Salmo salar are of international socioeconomic value, and the process of domestication has resulted in significant behavioural, morphological, and allelic differences from wild populations. Substantial evidence indicates that direct genetic interactions or interbreeding between wild and escaped farmed Atlantic salmon occurs...

Increasing conservation and animal-welfare concerns have driven the development of non-lethal sampling of fish populations, with the use of muscle tissue biopsies now being routinely applied as a sampling method in the wild. Crucial to the success of non-lethal sampling, however, is an evaluation of the short-and long-term consequences of the treat...

Acoustic and archival telemetry were used to study the marine movements of 115 anadromous Arctic char (Salvelinus alpinus) at two sites in southern Labrador, Canada, in relation to daily variation in temperature and depth use, body size, and their effects on marine activity patterns. Although evidence varied between locations, Arctic char generally...

Migratory behaviour may vary according to the life history and demographic attributes of fish and lead to the spatial segregation of distinct population segments during the non-breeding season. In adult Atlantic salmon, spawning history differences are associated with intra-population variation in marine movements, but the degree of connectivity in...

Anadromous Arctic charr, Salvelinus alpinus, migrate back to freshwater in late summer to spawn and/or overwinter. While seasonal movement patterns during the freshwater residency period are generally understood, specifics of the short temporal activity patterns remain poorly characterized. This study used temperature and accelerometer sensing tele...

Ocean Frontier Institute, Module J

Owing to the iteroparous nature of Atlantic salmon (Salmo salar), a seaward migrating cohort may consist of juveniles and adults that differ in size, maturity, experience, and in the motivation and consequences of migratory movements. Few studies have investigated the role of ontogeny in shaping intrapopulation variability in movement patterns amon...

We investigated the response of Atlantic salmon (Salmo salar) to capture and handling stressors by analyzing fine-scale locomotor activity using accelerometer data loggers and broader-scale movements by tracking migration with radiotelemetry. Half the sample population was exposed to experimental exercise and air exposure and released with a contro...

Throughout their native range, wild Atlantic salmon populations are threatened by hybridization and introgression with escapees from net‐pen salmon aquaculture. Although domestic‐wild hybrid offspring have shown reduced fitness in lab and field experiments, consequential impacts on population abundance and genetic integrity remain difficult to pred...

ABSTRACT: Genetic interactions (i.e. hybridization) between wild and escaped Atlantic salmon Salmo salar from aquaculture operations have been widely documented, yet the ability to incorporate predictions of risk into aquaculture siting advice has been limited. Here we demonstrate a model-based approach to assessing these potential genetic interact...

Escaped farmed Atlantic salmon interbreed with wild Atlantic salmon, leaving offspring that often have lower success in nature than pure wild salmon. On top of this, presence of farmed salmon descendants can impair production of wild‐type recruits. We hypothesize that both these effects connect with farmed salmon having acquired higher standard met...

Hybridization of escaped farmed Atlantic salmon Salmo salar with wild populations occurs throughout their native range and can threaten wild population stability and persistence. The extent of hybridization is often population-specific and can drive changes in phenotype and genotype. Current understanding of the forces that contribute to the spatia...

Domestication is rife with episodes of interbreeding between cultured and wild populations, potentially challenging adaptive variation in the wild. In Atlantic salmon, Salmo salar, the number of domesticated individuals far exceeds wild individuals, and escape events occur regularly, yet evidence of the magnitude and geographic scale of interbreedi...

Anadromous Arctic char (Salvelinus alpinus) migrate back to fresh water in late summer to spawn and (or) overwinter. Upon freshwater entry, feeding is reduced or absent, and movement activity is restricted. While the physiological responses to low temperatures (e.g., growth, metabolism) are understood, specifics of the use of thermal habitat for ov...

Farmed fish that escape and mix with wild fish populations can have significant ecological and genetic consequences. To reduce the number of escaped fish in the wild, recapture is often attempted. Here, we review the behaviours of escapees post-escape, and how recapture success varies with escaped fish size, the size of the initial escape event and...

SUMMARY OF RECOMMENDATIONS • Stocking of non-native species and populations of salmonids should be avoided • Monitoring, reporting and evaluation of stocking and transfer activities in countries such as Germany, France, Norway and Sweden are generally lacking or insufficient, and therefore should be improved • Local and regional authorities shou...

Anadromous Arctic charr, Salvelinus alpinus, feed in the marine environment for several months during the summer and migrate back to fresh water in late summer to spawn and/or overwinter. While overwintering, anadromous Arctic charr are generally believed to reduce or cease feeding, and they are poorly described in their winter movement activity. T...

The limited energy individuals acquire has to be procured for different purposes to ensure survival and successful reproduction. Energy is allocated to different purposes including somatic growth, energy storage and breeding. Brown trout has a wide distribution where environmental conditions vary both on geographical and seasonal basis. Brown trout...

1.A phenotypic syndrome refers to complex patterns of integration among functionally related traits in an organism that defines how the organism interacts with its environment and sustains itself. 2.Human-induced biological invasions have become important sources of environmental modifications. However, the extent to which invasive species affect...

The notion that cultured fishes develop a morphology that differs from their wild conspecifics has become nearly axiomatic. A commonly supervened corollary is that exposure to culture causes predictable and consistent morphological changes that together form a common “cultured phenotype”. While this is often asserted, it has not been formally teste...

Landscape genetics affords a potential analysis framework to evaluate the effect of contemporary land use on endangered species at a population level. However, historical patterns of population connectivity need to be accounted for prior to testing for the contemporary effect of threats. The goals of this study were to (1) optimally describe histor...

Environmental heterogeneity can combine with evolutionary responses to create very dynamic and often locally independent populations across a landscape. Such complexity creates difficulties for managers trying to conserve populations across large areas. This study develops, applies, and tests the use of stochastic life-history modeling and Monte Ca...

Aquaculture is an increasingly important food-producing sector, providing protein for human consumption. However, marine aquaculture often struggles for space due to the crowded nature of human activities in many marine coastal areas, and because of limited attention from spatial planning managers. Here, we assess the need for coastal spatial plann...

Differences in sperm metabolism and morphology between wild and non-local farmed Atlantic salmon Salmo salar were assessed by measuring metabolic enzyme activities and length of sperm flagella. No differences were observed between wild and farmed S. salar sperm with regards to cell counts or any of the biochemical variables assessed. Flagella of sp...

The performance of aquaculture escapees in the wild depends in part on how their morphology differs from that of wild fish. We compared farmed Atlantic cod (Gadus morhua) morphology to that of wild cod from the same ancestral population. Traditional and geometric morphometrics showed that farmed cod had relatively smaller fins, heads, eyes, and jaw...

Culture of Atlantic cod Gadus morhua L. has been proposed as a means of diversifying the aquaculture industry in Canada and other countries within its native range. Lessons gleaned from aquaculture of salmonids suggest that escapes and interactions with wild fish are inevitable. Here, we studied the reproductive interactions of individual cultured...

Salmon produced by hatcheries have lower fitness in the wild than naturally produced salmon, but the factors underlying this difference remain an active area of research. We used genetic parentage analysis of alevins produced by experimentally mixed groups of wild and hatchery coho salmon (Oncorhynchus kisutch) to quantify male paternity in spawnin...

This study tested the hypothesis that the effects of Atlantic cod Gadus morhua ovarian fluid on sperm motility variables are population specific. Sperm from a northern G. morhua population were activated in the presence of ovarian fluid from either northern or southern G. morhua at different concentrations. Ovarian fluid acted as a filter, in some...

Captive rearing programs (hatcheries) are often used in conservation and management efforts for at-risk salmonid fish populations. However, hatcheries typically rear juveniles in environments that contrast starkly with natural conditions, which may lead to phenotypic and/or genetic changes that adversely affect the performance of juveniles upon the...

Fish scales have long been used to reconstruct fine-scale habitat transitions such as the movement of juvenile fish from freshwater, estuary, and ocean environments. Despite the importance of life history information to fisheries management and conservation, few studies have validated that scale morphology accurately describes fish movement between...

Aquaculture companies operating along the south coast of Newfoundland have requested permission to use farmed European-origin Atlantic salmon in their operations to increase their competitiveness. Canada’s National Code on Introductions and Transfers of Aquatic Organisms requires that a risk assessment be conducted in evaluating requests for import...

As natural populations decline, captive breeding and rearing programs have become essential components of conservation efforts. However, captive-rearing can cause unintended phenotypic and/or genetic changes that adversely impact on population restoration efforts. Here, we test whether the exposure of captive-reared Atlantic salmon (Salmo salar) to...

Genetic interaction between farmed escapees and wild conspecifics represents one of the major environmental challenges faced by the Atlantic salmon aquaculture industry. In order to mitigate genetic interactions, triploid (sterile) farmed fish can be produced. However, triploids may still develop secondary sexual characteristics, and potentially at...

Biological invasions create complex eco-logical and societal issues worldwide. Most of the knowledge about invasions comes only from success-ful invaders, but less is known about which processes determine the differential success of invasions. In this review, we develop a framework to identify the main dimensions driving the success and failure of...

Captive rearing is being used increasingly to maintain demographics and genetic diversity of threatened fish populations and species, but its effectiveness can be hindered by domestication, that is, inadvertent selection for performance in captivity at the cost of that in the wild. Some captive rearing programmes have begun to take steps to limit s...

Should growth hormone (GH) transgenic Atlantic salmon escape, there may be the potential for ecological and genetic impacts on wild populations. This study compared the developmental rate and respiratory metabolism of GH transgenic and non-transgenic full sibling Atlantic salmon during early ontogeny; a life history period of intense selection that...

Atlantic cod escape from fish farms at higher rates than commonly cultured marine species, and escapees have been observed to interact with wild fish in mating aggregations. Previous research suggests that potential interbreeding is mediated largely by the likelihood of wild males spawning with escaped females, and as such, the egg and ovarian flui...

Adaptations at the gamete level (a) evolve quickly, (b) appear sensitive to inbreeding and outbreeding and (c) have important influences on potential to reproduce. We apply this understanding to problems posed by escaped farm salmon and measure their potential to reproduce in the wild. Farm Atlantic salmon (Salmo salar) are a threat to biodiversity...

Atlantic cod escape from fish farms at higher rates than commonly cultured marine species, and escapees have been observed to interact with wild fish in mating aggregations. Previous research suggests that potential interbreeding is mediated largely by the likelihood of wild males spawning with escaped females, and as such, the egg and ovarian flui...

Sexual selection is often prevented during captive breeding in order to maximize effective population size and retain genetic diversity. However, enforcing monogamy and thereby preventing sexual selection may affect population fitness either negatively by preventing the purging of deleterious mutations or positively by reducing sexual conflicts. To...

Atlantic cod is a key species of the North Atlantic ecosystem whose distribution will likely be affected by climate change. Although general temperature effects on reproduction are known, there is a dearth of information on population and individual level life history and reproductive plasticity responses to temperature change. We tested the hypoth...

The success of invasive species is frequently attributed to phenotypic plasticity, which facilitates persistence in novel environments. Here we report on experimental tests to determine whether the intensity of cryptic coloration patterns in a global invader (brown trout, Salmo trutta) was primarily the result of plasticity or heritable variation....

Interspecific hybridization is a route for transgenes from genetically modified (GM) animals to invade wild populations, yet the ecological effects and potential risks that may emerge from such hybridization are unknown. Through experimental crosses, we demonstrate transmission of a growth hormone transgene via hybridization between a candidate for...

Inherent trait differences and changes that arise through domestication could be maladaptive and lead to negative ecological consequences when non-native individuals escape from aquaculture cages and interact with wild populations. We used acoustic telemetry to map the spatiotemporal distribution of local wild (n = 29) and “escapee” farmed Atlantic...

Adaptive evolutionary change in only a few generations can increase the ability of non-native invasive species to spread, and yet adaptive divergence is rarely assessed in recently established populations. In this study, we experimentally test for evidence of fine-scale local adaptation in juvenile survival and growth among three populations of an...

Climate change, fishing, and aquaculture have affected and will continue to influence Canadian marine biodiversity, albeit at different spatial scales. The Arctic is notably affected by reduced quality and quantity of sea ice caused by global warming, and by concomitant and forecasted changes in ocean productivity, species ecology, and human activi...

Climate change, fishing, and aquaculture have affected and will continue to influence Canadian marine biodiversity, albeit at different spatial scales. The Arctic is notably affected by reduced quality and quantity of sea ice caused by global warming, and by concomitant and forecasted changes in ocean productivity, species ecology, and human activi...

Canada has made numerous national and international commitments to sustain marine biodiversity. Given current and potential threats to biodiversity from climate change, fisheries, and aquaculture, we provide a summary review of Canada's progress in fulfilling its obligations to protect, conserve, recover, and responsibly exploit marine biodiversity...

Canada has made numerous national and international commitments to sustain marine biodiversity. Given current and potential threats to biodiversity from climate change, fisheries, and aquaculture, we provide a summary review of Canada’s progress in fulfilling its obligations to protect, conserve, recover, and responsibly exploit marine biodiversity...

A suite of characteristics is often used to assess egg quality as these properties potentially play important roles in progeny survival and growth. Our objective was to assess egg characteristics including lipid biocomposition of an iteroparous, batch-spawning teleost of wild origin. Maternal allocation to egg number was generally dome-shaped (5 of...

The escape of fish from aquaculture is a persistent economic problem for farmers as well as an environmental problem that threatens wild fish population as a consequence of potential negative ecological and genetic interactions. Farmed Atlantic cod (Gadus morhua) cause significant damage by biting the net and creating holes through which they escap...

We explored the mechanisms of density-dependent growth in Arctic char (Salvelinus alpinus) by comparing the energetics of growth, consumption, and activity obtained under three replicated density treatments in a large-scale enclosure (90 m² surface area) experiment. The enclosures permitted the entry of zooplankton and allowed char to feed on the b...

This study investigated the importance of competition with brown trout Salmo trutta as a driver of the morphological and behavioural divergence of two morphs of Arctic charr Salvelinus alpinus. The morphs originated from two lakes differing in absence or presence of the competitor. The bioenergetics and behaviour of S. alpinus were quantified in re...

Biological invasions represent one of the greatest threats to aquatic ecosystems, particularly in locations a high degree of isolation and endemism, such as southern South America. In this region, salmonids are top-level invaders, but information about their dispersal, persistence, and population dynamics is still limited. Here, we used available h...

1. Although life-history theory predicts that juvenile growth rates should be high, there is substantial evidence that most juveniles grow below their physiological maximum. The endocrine system plays an important role in the determination of fundamental life-history traits, and hormones often serve as a link between an organism’s environment and t...

Sexually selected traits are expected to evolve to a point where their positive effect on reproductive success is counterbalanced by their negative effect on survival. At the genetic level, such a trade-off implies antagonistic pleiotropy between survival and the expression of sexually selected traits. Yet, the consequences of such a genetic archit...

1. Understanding the proximate and ultimate mechanisms shaping the expression of alternative reproductive phenotypes is a fundamental question in life-history evolution. Precocial maturation in fishes, one such alternative phenotype, has been thought to reflect rapid growth and/or energy accumulation; however, mechanistically linking these specific...

Background: Brown trout (Salmo trutta) were introduced into, and subsequently colonized, a number of disparate watersheds on the island of Newfoundland, Canada (110,638 km(2)), starting in 1883. Questions: Do environmental features of recently invaded habitats shape population-level phenotypic variability? Are patterns of phenotypic variability sug...

This chapter documents striking variability in life history traits and reproductive behaviour among fishes, before giving an account of the mechanisms that control these traits, including the stimuli that promote or suppress reproductive behaviours and the neuroendocrine process that generate them. The development of reproductive behaviour under th...